Capacitance type transducer and acoustic sensor

A capacitance type transducer, comprising:

• a substrate with an opening on a surface thereof;
• a back plate arranged to oppose the opening of the substrate;
• and
• a vibrating electrode film arranged to oppose the back plate across a gap between the vibrating electrode film and the back plate,
• wherein the capacitance type transducer converts a displacement of the vibrating electrode film into a change in capacitance between the vibrating electrode film and the back plate,
• wherein the capacitance type transducer further comprises a pressure releasing flow channel which is an air flow channel formed by a gap between a part of the vibrating electrode film and a protruding portion integrally provided on the back plate and which is configured to, when the vibrating electrode film deforms under pressure, release the pressure applied to the vibrating electrode film by increasing a flow channel area due to a relative movement of the vibrating electrode film and the protruding portion integrally provided on the back plate,
• wherein the protruding portion is a protruding pillar structure,
• wherein the pressure releasing flow channel is formed by a gap between a hole provided in the vibrating electrode film and a protruding pillar structure integrally provided from the back plate to a side of the vibrating electrode film,
• wherein at least a tip section of the protruding pillar structure has a smaller diameter than a diameter of the hole and the protruding pillar structure penetrates into the hole in a state prior to the vibrating electrode film deforming under pressure, and
• wherein, when the vibrating electrode film deforms under pressure, the pressure applied to the vibrating electrode film is released as the vibrating electrode film and the protruding pillar structure of the back plate relatively move and the penetration of the protruding pillar structure into the hole is canceled.

A capacitance type transducer, comprising:

• a substrate with an opening on a surface thereof;
• a back plate arranged to oppose the opening of the substrate;
• and
• a vibrating electrode film arranged to oppose the back plate across a gap between the vibrating electrode film and the back plate,
• wherein the capacitance type transducer converts a displacement of the vibrating electrode film into a change in capacitance between the vibrating electrode film and the back plate,
• wherein the capacitance type transducer further comprises a pressure releasing flow channel which is an air flow channel formed by a gap between a part of the vibrating electrode film and a protruding portion integrally provided on the back plate and which is configured to, when the vibrating electrode film deforms under pressure, release the pressure applied to the vibrating electrode film by increasing a flow channel area due to a relative movement of the vibrating electrode film and the protruding portion integrally provided on the back plate,
• wherein the protruding portion is a protruding pillar structure,
• wherein the pressure releasing flow channel is formed by a gap between a hole provided in the vibrating electrode film and a protruding pillar structure integrally provided from the back plate to a side of the vibrating electrode film,
• wherein the protruding pillar structure has a larger diameter than a diameter of the hole and a tip of the protruding pillar structure covers the hole from a side of the back plate in a state prior to the vibrating electrode film deforming under pressure, and
• wherein, when the vibrating electrode film deforms under pressure, the pressure applied to the vibrating electrode film is released as the vibrating electrode film and the protruding pillar structure of the back plate relatively move and the tip of the protruding pillar structure separates from the hole.